dom_hubbub_parser_destroy crash

This has been happening randomly since I updated NetSurf, so it
appears to have been caused by a change within the last week.

I can't provide anything other than the stack trace at this time,
unfortunately.

Stack trace:
libdom.so.0:dom_hubbub_parser_destroy()+0x1c (section 12 @ 0xC20)
[render/html.c:135] NetSurf:html_box_convert_done()+0x280 (section 8 @ 0x114FF4)
[render/box_construct.c:562] NetSurf:convert_xml_to_box()+0x330 (section 8 @ 0x1058D8)
[amiga/schedule.c:176] NetSurf:schedule_run()+0x144 (section 8 @ 0x52288)
[amiga/gui.c:2485] NetSurf:gui_poll()+0x44 (section 8 @ 0x2199C)
[desktop/netsurf.c:250] NetSurf:netsurf_main_loop()+0x30 (section 8 @ 0xD5DF8)
[amiga/gui.c:946] NetSurf:main()+0x36c (section 8 @ 0x1CFE4)
native kernel module newlib.library.kmod+0x00002094
native kernel module newlib.library.kmod+0x00002cf4
native kernel module newlib.library.kmod+0x00002eb8
NetSurf:_start()+0x170 (section 8 @ 0x170)
native kernel module dos.library.kmod+0x00022d9c
native kernel module kernel+0x0003bd20
native kernel module kernel+0x0003bda0

Regards
Chris